Near field communication (NFC) is a form of short-range wireless communication where an antenna that is smaller than a wavelength of the carrier signal may be used to transmit the carrier signal. In the near-field (approximately one quarter of a wavelength), the antenna may produce an electric field, a magnetic field, etc.
However, some forms of NFC may require that the transmitter and receiver be (i) in close proximity (e.g., 10 mm or less), (ii) within a line of sight, or both. Such usage restrictions may limit the applications in which NFC can be used.